let s = Symbol()
let s2 = Symbol()
console.log(s == s2);
/*[s]变量 s字符串*/
let obj = {
    [Symbol()]: function (arg) {
        console.log('----');

    },
    [Symbol()]: function (arg) {
        console.log('++++');

    }
}
/* console.log(obj); */
for(let key in obj){
    console.log(key);
}
console.log(Object.keys(obj));
console.log(Object.getOwnPropertyNames(obj));
console.log(Object.getOwnPropertySymbols(obj));
Object.getOwnPropertySymbols(obj).forEach(item=>{
    console.log(obj[item]());
})